1. Technical Field
The present disclosure relates generally to a tool for making or breaking a threaded connection between adjacent drilling components, such as drill rods.
2. Related Technology
Drilling rigs are often used for drilling holes into various substrates. Such drill rigs often include a drill head mounted to a generally vertically oriented mast. The rig can include mechanisms and devices that are capable of moving the drill head along at least a portion of the mast. The drill head may include mechanisms that receive and engage the upper end of a drilling rod or pipe. Conventional drilling processes include the utilization of specialized lengths of pipe with threaded ends, commonly referred to as drill rods. These drill rods are screwed together at the ends to form a continuous length of pipe, sometimes referred to as a rod string or drill string. The end of the rod string coupled to the drill head may be referred to as the head end or box end. The drill string may further include a cutting bit or other device on the end opposite the head end, referred to as the bit end or pin end of the drill string. The drill string may include multiple rods each having a length that is shorter than the usable length of the mast. Screwing two lengths of drill pipe together is commonly referred to as making the joint, while unscrewing two rods is commonly referred to as breaking the joint.
The drill head may apply a force to the drilling rod or pipe which in turn is transmitted to the drill string. If the applied force is a rotational force, the drill head may thereby cause the drill string to rotate within the bore hole. The rotation of the drill string may include the corresponding rotation of the cutting bit, which in turn may result in a cutting action. The forces applied by the drill head may also include an axial force, which may be transmitted along the drill string to facilitate penetration into the substrate.
In a conventional drill string, the head end of a drill rod is coupled to the drill head and the bit end of the drill rod is coupled to the head end of the next drill rod in the drill string and so on. During the drilling process, the drill head is typically advanced from an upper position on the mast until the drill head approaches the lower end of the mast. Once the drill head has reached the lower end, a clamp or other device is used to maintain the drill string in position relative to the mast. A breakout tool may then be used to break the joint between the drill string and the drill head. The drill head may then be disconnected from the drill string via counter-rotation of the drill head. The drill head is then raised to the upper end of the mast in preparation to receive another drilling pipe. A new length of drilling pipe is then positioned along the centerline of the mast and the drill head is rotatingly coupled to the new drilling pipe to a manufacturer-specified torque. The drill head may then be lowered such that the bit (male) end of the drill pipe may be engaged into the head (female) end of the drill string and the new drill pipe is rotated into the top of the exposed drill pipe in order to accurately make the joint. The new joint may be rotated until a manufacturer-specified torque is achieved. A breakout tool may also be used in the process of making the new joint. This process is continually repeated as the drilling of the borehole continues until the desired depth is reached. Following the achievement of the desired depth, or if the bit wears out and needs to be replaced, the lengths of drill pipe must be withdrawn from the bore hole.
In order to remove the lengths of drill pipe, a clamp is applied below the joint between the drill string and the drill head with the drill head being located at the lower end of the drill rig mast. Once again, a break out tool may be applied to break the joint between the drill head and the drill string. Once the drill head is disconnected from the drill string, a hoisting device may be used to raise the drill string until a full length of drill rod is exposed out of the bore hole. The drill string is then clamped below an exposed lower joint to be broken. The exposed lower joint may be broken and the drill rod removed via the hoisting device or other particular rod handling means on the drilling rig.
Many tools have traditionally been used for making and breaking threaded drill rod joints as discussed above. Conventional methods include the use of hand tools, such as wrenches, or modified hand tools attached to hydraulic cylinders. One additional conventional method includes the use of a rod spinner. A rod spinner is a device usually fixed to the mast of a drill rig and through the center of which passes the rod string. The rod spinner may include a motor and corresponding mechanism for gripping and rotating the outer surface of a drill rod in order to make and break joints. Accordingly, a rod spinner may grip and rotate the drill rod located above a joint, while a lower drill rod or drill string located below the joint is clamped to the mast using a foot clamp or other similar clamping device.
Conventional rod spinners often are unable to selectively engage a rod string when needed and retract when not in use. This results from the fact that the drill string typically passes through the center of conventional rod spinners thereby requiring that a drill string joint be broken prior to engaging or retracting the rod spinner. Conventional rod spinners normally stay in place while the rod string is being removed from or replaced back into the drill hole. As such, the rod string is pulled or fed through the center of the rod spinner until all the required lengths of rods were removed from the hole, which may inconvenience and hinder the drilling process and limit the use of rod spinners. Disadvantages also exist in relation to conventional mechanisms used in rod spinners for gripping and rotating drill rods to make and break joints.
The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one example technology area where some embodiments described herein may be practiced.